1. Field of the Invention
The present invention relates to a micro-reactor for biological substance inspection and a biological substance inspection device including the micro-reactor.
2. Description of the Related Art
By free use of micro machine technology and micromachining technology, development efforts have been made in recent years to create a system wherein the conventional apparatus and measures for preparation of a sample, chemical analysis and chemical synthesis' (e.g. a pump, valve, flow path and sensor) are formed into minute structures, and are integrated on one chip. This is also called the μ-TAS (Micro total Analysis System), bioreactor or lab-on-chip or biochip. Its application is anticipated in the field of medical examination, diagnosis, environmental measurement and agricultural production. As can been seen especially in the field of genetic screening, when a complicated process, advanced manual skill and machine operation technique are involved, an automated, high-speed, simplified micronized analysis system brings about immeasurable advantages of permitting analysis independently of time and place, in addition to various advantages in terms of costs, required quantity of samples and required time.
In the field of various inspections including the clinical examination, primary importance is attached to quantitative analysis, precision of analysis and economy in the chip for analysis capable of producing speedy results independently of place. Since the chip for analysis is subjected to severe restrictions for the size and configuration, it is important to establish a highly reliable liquid feed system of simple structure. Thus, there has been an active demand for a reliable, high-precision micro fluid control device. The present inventors have already proposed a micro pump system capable of meeting such requirements (Official Gazette of Japanese Patent Tokkai 2001-322099 and Official Gazette of Japanese Patent Tokkai 2004-108285).
One of the most important required tasks of the micro-reactor is to provide a method for analysis capable of minimizing the amount of the required sample and reagent. To achieve this purpose, the liquids (samples or reagents) must be mixed efficiently in a mixing flow path or a reaction chamber. Further, a mechanism capable of simple and highly sensitive detection and determination of a trace quantity of reaction products must also be mounted on the chip. In the detection of a gene, it is a common practice to use the amplification reaction by the PCR (Polymerase Chain Reaction) method, and its usefulness is extensively recognized. However, since the PCR allows a trace quantity of genes present in the sample to be amplified hundreds of thousands through several millions times, it will have a serious impact of cross contamination carry-over and contamination. Frequent reading errors during amplification of the DNA are often pointed out. In the immunoassay, it is necessary to eliminate the possibility of nonspecific interaction. If such latent disadvantages in analysis are neglected, a wrong conclusion may be reached due to incorrect results. In the micro-reactor, it is necessary to configure an analysis system where adequate steps are taken to address such problems.
A large volume of samples, particularly the chips using clinical samples subjected to possible contamination and infection, should preferably be disposable. It is necessary to solve problems involved in a great variety of uses and production costs.
The micro-reactor providing a simple and quick inspection measure raises specific problems to be solved in practical use, and these problems have been expected to be solved.
[Patent Document 1] Official Gazette of Japanese Patent Tokkai 2001-322099
[Patent Document 2] Official Gazette of Japanese Patent Tokkai 2004-108285
[Non-Patent Document 1] KIMIZUKA Fusao and KATO Kuninoshin: “DNA Chio Technology and its Application”, “Protein, Nucleic acid and Enzyme” Vol. 43, No. 13, (1998), Kyoritsu Publishing Co., Ltd.